Systems and methods for estimating ultrafiltration rates

ABSTRACT

Systems and methods for estimating the post-treatment ultrafiltration rate of a patient are provided. A medical device can be configured to determine an estimated post-treatment ultrafiltration rate based on one or more values associated with a patient prepared to undergo treatment with the medical device. The medical device can also be configured to compare the estimated post-treatment ultrafiltration rate with one or more threshold values. The medical device can be configured to have an alert module, which can be activated when the estimated post-treatment ultrafiltration rate exceeds the one or more threshold values.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation application of and claims priority toU.S. application Ser. No. 16/234,716, filed on Dec. 28, 2018.

TECHNICAL FIELD

This disclosure generally relates to systems and methods for estimatingultrafiltration rates.

BACKGROUND

Certain extracorporeal blood treatment systems, such as dialysissystems, use ultrafiltration to remove fluid from a patient undergoingdialysis treatment. Ultrafiltration generally refers to membranefiltration in which forces like pressure lead to a separation through asemipermeable membrane. Suspended solids and solutes of high molecularweight can be retained in a retentate, while water and low molecularweight solutes pass through the membrane in the filtrate.Ultrafiltration rate generally refers to the rate at which fluid isremoved from a patient's body during a dialysis treatment. Excessiveultrafiltration rates may be a major source of morbidity and mortalityfor dialysis treatments. Because of these hazards, dialysis providersmay be required to report ultrafiltration rates to agencies, such as tothe Centers for Medicare & Medicaid Services (CMS) as part of qualityincentive programs (QIPs).

SUMMARY

In at least one aspect of the present disclosure, a medical device isprovided. The medical device includes a display device, acomputer-readable medium that includes computer-executable instructions,one or more processors configured to execute the computer-executableinstructions, an alert module configured to be communicatively coupledto the one or more processors and produce an alert, and a user interfaceconfigured to be communicatively coupled to the one or more processors.When the one or more processors are executing the computer-executableinstructions, the one or more processors are configured to carry outoperations to cause the display device to display the user interface,receive, through the user interface, one or more values associated witha user of the medical device, determine an estimated post-treatmentultrafiltration rate based on the one or more values, compare thepredicted post-treatment ultrafiltration rate to an ultrafiltration ratethreshold value, and cause the alert module to produce an alert if thepredicted post-treatment ultrafiltration rate exceeds theultrafiltration rate threshold value.

The one or more values associated with the user can include the user'scurrent weight. The one or more values associated with the user caninclude a target dry weight of the user. The one or more valuesassociated with the user can include an additional volume of fluidentering the user's body during a treatment session. The one or morevalues associated with the user can include an ultrafiltration time.

The alert module can be configured to produce an audible alert. Thealert module can be configured to produce a visual alert. The alertmodule can be configured to cause the display device to render a visualalert. The medical device can be a dialysis machine.

The ultrafiltration rate threshold value can be 13.0 mL/kg/hr. The oneor more processors can be configured to dynamically determine theestimated post-treatment ultrafiltration rate while the user isundergoing treatment with the medical device. The one or more processorsare configured to determine the estimated post-treatment ultrafiltrationrate according to the formula:

$\frac{\begin{matrix}{\left( {{{Current}\mspace{14mu}{Weight}} - {DryWeightTarget}} \right)*} \\{1000 + {AdditionalFluidVolume}}\end{matrix}}{{UFTime}*{DryWeightTarget}}.$

According to another aspect of the present disclosure, a method includescausing a display device of a medical device to display a userinterface. The method includes, receiving, through the user interface,one or more values associated with a user of the medical device. Themethod includes determining a post-treatment ultrafiltration rate basedon the one or more values. The method includes comparing the predictedpost-treatment ultrafiltration rate to an ultrafiltration rate thresholdvalue. The method includes causing an alert module associated with themedical device to produce an alert if the predicted post-treatmentultrafiltration rate exceeds the ultrafiltration rate threshold value.

The one or more values associated with the user can include the user'scurrent weight. The one or more values associated with the user caninclude a target dry weight of the user. The one or more valuesassociated with the user can include an additional volume of fluidentering the user's body during a treatment session. The one or morevalues associated with the user can include an ultrafiltration time.

The alert can be an audible alert. The alert can be a visual alert. Thealert can be rendered on the display device through the user interface.The medical device can be a dialysis machine.

The ultrafiltration rate threshold value can be 13.0 mL/kg/hr. Theestimated post-treatment ultrafiltration rate can be determineddynamically while the user of the medical device is undergoing treatmentwith the medical device. Determining a post-treatment ultrafiltrationrate can include using the formula

$\frac{\begin{matrix}{\left( {{{Current}\mspace{14mu}{Weight}} - {DryWeightTarget}} \right)*} \\{1000 + {AdditionalFluidVolume}}\end{matrix}}{{UFTime}*{DryWeightTarget}}.$

Implementations can include one or more of the following advantages. Insome implementations, an extracorporeal blood treatment (ECBT) system isconfigured to estimate a post-treatment ultrafiltration rate for apatient before the patient undergoes dialysis treatment and/or while thepatient is undergoing treatment. This can allow a medical provider todetermine whether changes should be made to the treatment plan before orduring the treatment process. In some implementations, the ECBT systemis configured to generate an alert to notify the medical provider and/orthe patient when the estimated ultrafiltration rate exceeds a thresholdvalue. Thus, this disclosure provides an improvement to conventionalECBT systems that were previously incapable of determining projectedultrafiltration rates at treatment's end and alerting users when theECBT system is being operated at high ultrafiltration rates before apatient undergoes medical treatment.

These and other aspects, features, and implementations can be expressedas methods, apparatus, systems, components, program products, means orsteps for performing a function, and in other ways.

These and other aspects, features, and implementations will becomeapparent from the following descriptions, including the claims.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows an example of a system including an extracorporeal bloodtreatment machine to estimate ultrafiltration rates.

FIG. 2 shows a flowchart depicting an example of a method 200 forestimating ultrafiltration rates according to one or more embodiments ofthe present disclosure.

FIG. 3 is a front perspective view of a hemodialysis system.

FIG. 4 is a front perspective view of the hemodialysis system of FIG. 3with a door of a module of the hemodialysis system in an open positionto expose a blood component secured to the module.

FIG. 5 is a schematic showing the flow paths of fluids into, through,and out of the blood circuit and the dialysate circuit of thehemodialysis system.

FIG. 6 is a schematic of fluid flow through the blood circuit anddialysate circuit of the hemodialysis system of FIG. 3 when thehemodialysis system is connected to a patient for treatment.

DETAILED DESCRIPTION

Conventional ultrafiltration rate calculations typically consider thepatient's weight post-dialysis treatment. While, an actual post weightvalue is not available prior to or during an extracorporeal bloodtreatment (e.g., a dialysis treatment), it may be desirable to improvethe effectiveness and performance of an extracorporeal blood treatmentmachine by providing the machine with means to predict the projectedtreatment end final individual ultrafiltration rate (UFR) of a patientbefore the patient undergoes treatment with the machine.

The present disclosure provides systems and methods for estimating thepost-treatment ultrafiltration rate of a patient before the patientundergoes treatment. An extracorporeal blood treatment (ECBT) system canbe configured to determine an estimated post-treatment ultrafiltrationrate based on one or more values associated with a patient prepared toundergo treatment with the ECBT system. The ECBT system can also beconfigured to compare the estimated post-treatment ultrafiltration ratewith one or more threshold values. The ECBT system can be configured tohave an alert module, which can be activated when the estimatedpost-treatment ultrafiltration rate exceeds the one or more thresholdvalues. These systems and methods can be implemented to improveconventional ECBT systems that were previously incapable of determiningprojected treatment end final individual UFRs. These systems and methodscan also be implemented to improve use of conventional ECBT systems byenhancing clinical decision making at the point of care, and start ofindividual treatment, by ensuring the machines are able to provideprojected treatment end final individual UFR in terms of volume (e.g.,milliliters) per unit time (e.g., hours) per unit weight (e.g.,kilograms) such that the individual determination can best be maderegarding avoidance of high-risk ultrafiltration rates.

In the following description, for the purposes of explanation, numerousspecific details are set forth in order to provide a thoroughunderstanding of the present invention. It will be apparent, however,that the present invention may be practiced without these specificdetails. In other instances, well-known structures and devices are shownin block diagram form in order to avoid unnecessarily obscuring thepresent invention.

In the drawings, specific arrangements or orderings of schematicelements, such as those representing devices, modules, instructionblocks and data elements, are shown for ease of description. However, itshould be understood by those skilled in the art that the specificordering or arrangement of the schematic elements in the drawings is notmeant to imply that a particular order or sequence of processing, orseparation of processes, is required. Further, the inclusion of aschematic element in a drawing is not meant to imply that such elementis required in all embodiments or that the features represented by suchelement may not be included in or combined with other elements in someembodiments.

Further, in the drawings, where connecting elements, such as solid ordashed lines or arrows, are used to illustrate a connection,relationship, or association between or among two or more otherschematic elements, the absence of any such connecting elements is notmeant to imply that no connection, relationship, or association canexist. In other words, some connections, relationships, or associationsbetween elements are not shown in the drawings so as not to obscure thedisclosure. In addition, for ease of illustration, a single connectingelement is used to represent multiple connections, relationships orassociations between elements. For example, where a connecting elementrepresents a communication of signals, data, or instructions, it shouldbe understood by those skilled in the art that such element representsone or multiple signal paths (e.g., a bus), as may be needed, to affectthe communication.

Reference will now be made in detail to embodiments, examples of whichare illustrated in the accompanying drawings. In the following detaileddescription, numerous specific details are set forth in order to providea thorough understanding of the various described embodiments. However,it will be apparent to one of ordinary skill in the art that the variousdescribed embodiments may be practiced without these specific details.In other instances, well-known methods, procedures, components,circuits, and networks have not been described in detail so as not tounnecessarily obscure aspects of the embodiments.

Several features are described hereafter that can each be usedindependently of one another or with any combination of other features.However, any individual feature may not provide any of the advantagesdiscussed above or might only provide one of the advantages discussedabove. Although headings are provided, data related to a particularheading, but not found in the section having that heading, may also befound elsewhere in this description.

FIG. 1 shows an example of a system 100 including an extracorporealblood treatment (ECBT) machine 120 to estimate ultrafiltration rates.The ECBT machine 120 includes a display device 122 capable of renderinga user interface 123. The ECBT machine 120 also includes a plurality ofcomponents 121, an alert module 124, a computer-readable medium 113 andcomputer processors 117. The computer-readable medium 113 includescomputer-executable instructions 114.

The ECBT machine 120 can be configured to provide one or moreextracorporeal blood treatments, such as hemodialysis, hemofiltration,hemodiafiltration, ultrafiltration and/or other renal replacementtherapies. In any case, the ECTB machine 120 is configured to removefluid from a user (e.g., patient) of the ECBT machine 120. An example ofa ECTB machine 120 is discussed later in more detail with reference toFIG. 3.

The display device 122 can be an electronic display device. The displaydevice 122 can be configured to act as a touchscreen display device. Insome implementations, the user interface 123 is a graphical userinterface (GUI). The user interface 123 is configured to allow a user ofthe ECBT machine 120 to interact with the ECBT machine 120 throughgraphical icons and visual indicators. The user interface 123 can use awindows, icons, menus, pointer paradigm (WIMP) to allow a user tointeract with the ECBT machine 120. In some implementations, the userinterface 123 cooperates with the display device 122 to provide a userwith a touchscreen GUI. Additionally, or alternatively, the userinterface can include one or more input devices such as a mouse and/orkeyboard communicatively coupled with the ECBT machine 120. The userinterface 123 can also use a post-WIMP paradigm typically found intouchscreen-based GUIs. In some implementations, the user interface 123is configured to display images in the form of still photographs and/orvideos.

The user interface 123 can display information associated with the ECBTmachine 120. For example, the user interface 123 can show graphicalcharts and values associated with arterial pressure readings, venouspressure readings, dialysate flow rates, temperature readings, bloodpump rates, and so forth. In some implementations, the user interface123 displays a value associated with an estimated ultrafiltration rate(e.g., Est UFR). In some implementations, the user interface 123 promptsa user (e.g., medical personnel, patient, etc.) to input one or morevalues associated with a user of the ECBT machine 120. In someimplementations, the user interface 123 prompts the user to input theuser's current weight, target dry weight, an additional volume of fluid,and/or ultrafiltration time. A target dry weight refers to the desiredweight of a patient post-dialysis treatment and can be generallyassociated with a predicted weight of a patient who is euvolemic (e.g.,in normal fluid balance, such as if the patient were in a state ofnormal, healthy kidney function where normal urine output were present).Additional volume of fluid may refer to water, saline treatment, and soforth, which a patient may receive while undergoing dialysis treatment.Ultrafiltration time generally refers to the amount of time a patient isexpected to undergo dialysis treatment. As discussed later, these valuescan be used to determine an estimated ultrafiltration rate. The user canenter the values using the touchscreen of the display device 122, akeyboard, and/or any other device suitable for interacting with the userinterface 123.

The computer-readable medium 113 (or computer-readable memory) caninclude any data storage technology type which is suitable to the localtechnical environment, including but not limited to semiconductor basedmemory devices, magnetic memory devices and systems, optical memorydevices and systems, fixed memory, removable memory, disc memory, flashmemory, dynamic random-access memory (DRAM), static random-access memory(SRAM), electronically erasable programmable read-only memory (EEPROM)and the like. In some implementations, the computer-readable medium 113includes code-segment having executable instructions. In someimplementations, the computer-readable medium 113 stores informationcorresponding to the components 121 of the ECBT machine 120.

The alert module 124 is configured to produce an audible alert and/or avisual alert. For example, the alert module 124, can include means forproducing flashing/pulsed light (e.g., light bulbs, light-emittingdiodes, etc.). In some implementations, the pulsed light is red. In someimplementations, the alert module includes speakers. In someimplementation, the audible alert includes tones having one of severalfrequencies. In some implementations, the alert module 124 is integratedwith the user interface 123. For example, the user interface 123 candisplay boxes, such as a box that displays an estimated ultrafiltrationrate, which can flash certain colors that may command the attention of auser of the ECBT machine 120. The alert module 124 can also includemeans of providing a physical alert. For example, the alert module 124can include mechanisms configured to vibrate the ECBT machine 120 and/orbe placed on the body of a patient of the ECBT machine 120 to impartvibrations on the patient's body.

The computer processors 117 are communicatively coupled to the displaydevice 122, the user interface 123, and/or the alert module 124. In someimplementations, the computer processors 117 include a general purposeprocessor. In some implementations, the computer processors 117 includea central processing unit (CPU). In some implementations, the computerprocessors 117 include at least one application specific integratedcircuit (ASIC). The computer processors 117 can also include generalpurpose programmable microprocessors, special-purpose programmablemicroprocessors, digital signal processors (DSPs), programmable logicarrays (PLAs), field programmable gate arrays (FPGA), special purposeelectronic circuits, etc., or a combination thereof. The computerprocessors 117 are configured to execute program code means such as thecomputer-executable instructions.

When the computer processors 117 execute the computer-executableinstructions, the computer processors 117 carry out one or moreoperations. In some implementations, when the computer processors 117are executing the computer-executable instructions, the computerprocessors 117 carry out operations to cause the display device 122 todisplay the graphical user interface 123. As previously indicated, thegraphical user interface 123 can prompt the user to enter one or morevalues associated with a patient undergoing treatment using the ECBTmachine 120.

When the computer processors 117 are executing the computer-executableinstructions, the computer processors 117 carry out operations toreceive, through the user interface 123, one or more values associatedwith a user of the ECBT machine 120. For example, as indicated earlier,a patient or physician can enter values associated with a patientundergoing treatment with the ECBT machine 120, such as the patient'scurrent weight, target dry weight, an additional volume of fluid, and/orultrafiltration time. In some implementations, the values can bereceived by other sensor devices external and/or internal to the ECBTmachine 120. For example, the patient's current weight can be receivedfrom a weight sensor (e.g., scale) configured to measure the weight ofthe patient. The weight sensor can be integrated within the ECBT machine120 (e.g., underneath a seating arrangement) or it can be external tothe ECBT machine 120.

When the computer processors 117 are executing the computer-executableinstructions, the computer processors 117 carry out operations todetermine an estimated post-treatment ultrafiltration rate based on theone or more values. For example, in some implementations, the computerprocessors 117 determines an estimated post-treatment ultrafiltrationrate according to the following:

${{{Estimated}\mspace{14mu}{UFR}} = \frac{\begin{matrix}{\left( {{{Current}\mspace{14mu}{Weight}} - {DryWeightTarget}} \right)*} \\{1000 + {AdditionalFluidVolume}}\end{matrix}}{{UFTime}*{DryWeightTarget}}},$

where CurrentWeight is the weight of the patient at the time before thepatient undergoes treatment, DryWeightTarget is the desired weight ofthe patient after undergoing ultrafiltration treatment,AdditionalFluidVolume is an estimated volume of fluid which a patientmay receive while undergoing treatment, and UFTime is the amount of timethe patient will undergo ultrafiltration. In some implementations,weight is defined in terms of kilograms, volume is defined in terms ofmilliliters, and time is defined in terms of hours. However, eachvariable may be defined using other metrics, such as pounds, liters, andseconds, respectively. In some implementations, the computer processors117 determine an estimated post-treatment ultrafiltration rate before apatient begins treatment. In some implementations, the computerprocessors 117 determine an estimated post-treatment ultrafiltrationrate during treatment. In some implementation, the computer processors117 determine an estimated post-treatment ultrafiltration ratedynamically during treatment. For example, the computer processors 117can continuously updated the estimated post-treatment ultrafiltrationrate based on changed variables, such as a change in the time ofultrafiltration and/or change in volume of fluid received by thepatient.

When the computer processors 117 are executing the computer-executableinstructions 114, the computer processors 117 carry out operations tocompare the estimated post-treatment ultrafiltration rate with anultrafiltration rate threshold value. The ultrafiltration rate thresholdvalue can be based on, for example, healthcare standards and/or safetyconsiderations. In some implementations, the ultrafiltration ratethreshold value is 13.0 mL/kg/hr. In some implementations, the userinterface 123 is configured to prompt a user to input an ultrafiltrationrate threshold value. In some implementations, the ultrafiltration ratethreshold value is a set default value initialized by a manufacturer ormedical care personnel.

When the computer processors 117 are executing the computer-executableinstructions 114, the computer processors 117 carry out operations tocause the alert module 124 to produce an alert if the estimatedpost-treatment ultrafiltration rate exceeds the ultrafiltration ratethreshold. For example, if the estimated post-treatment ultrafiltrationrate exceeds 13.0 mL/kg/hr, the alert module 124 can be caused toproduce one or more visual alerts (e.g., flashing red light) and/or oneor more audible alerts (e.g., high-pitched beeping sound). The alertmodule 124 can also impart vibrations on the ECBT machine 120 or thepatient's body. In some implementations, the alert module 124 causes theuser interface 123 to display a visual alert. Alternatively, oradditionally, the alert module 124 includes a biofeedback algorithm,which is capable of controlling one or more operating parameters of theECBT machine 120 by adjusting the one or more operating parameters suchthat the estimated UFR is reduced.

FIG. 2 shows a flowchart depicting an example of a method 200 forestimating ultrafiltration rates according to one or more embodiments ofthe present disclosure. For illustrative purposes, the system 100 forestimating ultrafiltration rates performs the method 200 a. However, themethod 200 a may be performed by other systems that allow for estimatingfiltration rates. The method 200 a includes causing a display device todisplay a user interface (block 201), receiving values associated with auser (block 202), determining an estimated post-treatmentultrafiltration rate (block 203), comparing the predicted post-treatmentultrafiltration rate with a threshold value (block 204) and causing analert module to produce an alert if the estimated post-treatmentultrafiltration rate exceeds the threshold value (block 205).

At block 201, the computer processors 117 carry out operations to causedisplay device to display the graphical user interface 123. Aspreviously indicated, the graphical user interface 123 can prompt theuser to enter one or more values associated with a patient undergoingtreatment using the ECBT machine 120.

At block 202, the computer processors 117 carry out operations toreceive, through the user interface 123, one or more values associatedwith a user of the ECBT machine 120. For example, as indicated earlier,a patient or physician, can enter values associated with a patientundergoing treatment with the ECBT machine 120, such as the patient'scurrent weight, target dry weight, an additional volume of fluid, and/orultrafiltration time. In some implementations, the values can bereceived by other sensor devices external and/or internal to the ECBTmachine 120. For example, the patient's current weight can be receivedfrom a weight sensor (e.g., scale) configured to measure the weight ofthe patient. The weight sensor can be integrated within the ECBT machine120 (e.g., underneath a seating arrangement) or it can be external tothe ECBT machine 120.

At block 203, the computer processors 117 carry out operations todetermine an estimated post-treatment ultrafiltration rate based on theone or more values. For example, in some implementations, the computerprocessors 117 determines an estimated post-treatment ultrafiltrationrate according to the following:

${{{Estimated}\mspace{14mu}{UFR}} = \frac{\begin{matrix}{\left( {{{Current}\mspace{14mu}{Weight}} - {DryWeightTarget}} \right)*} \\{1000 + {AdditionalFluidVolume}}\end{matrix}}{{UFTime}*{DryWeightTarget}}},$

where CurrentWeight is the weight of the patient at the time before thepatient undergoes treatment, DryWeightTarget is the desired weight ofthe patient after undergoing ultrafiltration treatment,AdditionalFluidVolume is an estimated volume of fluid which a patientmay receive while undergoing treatment, and UFTime is the amount of timethe patient will undergo ultrafiltration. In some implementations, thecomputer processors 117 determine an estimated post-treatmentultrafiltration rate before a patient begins treatment. In someimplementations, the computer processors 117 determine an estimatedpost-treatment ultrafiltration rate during treatment. In someimplementation, the computer processors 117 determine an estimatedpost-treatment ultrafiltration rate dynamically during treatment. Forexample, the computer processors 117 can continuously updated theestimated post-treatment ultrafiltration rate based on changedvariables, such as a change in the time of ultrafiltration and/or changein volume of fluid received by the patient.

At block 204, the computer processors 117 carry out operations tocompare the estimated post-treatment ultrafiltration rate with anultrafiltration rate threshold value. The ultrafiltration rate thresholdvalue can be based on, for example, healthcare standards and/or safetyconsiderations. In some implementations, the ultrafiltration ratethreshold value is 13.0 mL/kg/hr. In some implementations, the userinterface 123 is configured to prompt a user to input an ultrafiltrationrate threshold value. In some implementations, the ultrafiltration ratethreshold value is a set default value initialized by a manufacturer ormedical care personnel.

At block 205, the computer processors 117 carry out operations to causethe alert module 124 to produce an alert if the estimated post-treatmentultrafiltration rate exceeds the ultrafiltration rate threshold. Forexample, if the estimated post-treatment ultrafiltration rate exceeds13.0 mL/kg/hr, the alert module 124 can be caused to produce one or morevisual alerts (e.g., flashing red light) and/or one or more audiblealerts (e.g., high-pitched beeping sound). The alert module 124 can alsoimpart vibrations on the ECBT machine 120 or the patient's body. In someimplementations, the alert module 124 causes the user interface 123 todisplay a visual alert.

FIG. 3 is a front perspective view of a hemodialysis system 300. FIG. 4is a front perspective view of the hemodialysis system 300 of FIG. 3with a door of a module of the hemodialysis system in an open positionto expose a blood component secured to the module. Referring to FIGS. 3and 4, the hemodialysis system 300 includes a hemodialysis machine 302to which a disposable blood component set 304 that forms a blood circuitis connected. In some implementations, the hemodialysis machine 302 isthe ECBT machine 120 of FIG. 1 and is configured to perform the method200 for estimating ultrafiltration rates as discussed earlier withreference to FIG. 2.

During hemodialysis, arterial and venous patient lines 306, 308 of theblood component set 304 are connected to a patient and blood iscirculated through various blood lines and components, including adialyzer 310, of the blood component set 304. At the same time,dialysate is circulated through a dialysate circuit formed by thedialyzer 310 and various other dialysate components and dialysate linesconnected to the hemodialysis machine 302. Many of these dialysatecomponents and dialysate lines are located inside the housing of thehemodialysis machine 302, and are thus not visible in FIGS. 3 and 4. Thedialysate passes through the dialyzer 310 along with the blood. Theblood and dialysate passing through the dialyzer 310 are separated fromone another by a semi-permeable structure (e.g., a semi-permeablemembrane and/or semi-permeable microtubes) of the dialyzer 310. As aresult of this arrangement, toxins are removed from the patient's bloodand collected in the dialysate. The filtered blood exiting the dialyzer310 is returned to the patient. The dialysate that exits the dialyzer310 includes toxins removed from the blood and is commonly referred toas “spent dialysate.” The spent dialysate is routed from the dialyzer310 to a drain.

The hemodialysis machine 302 includes a touch screen 318 and a controlpanel 320. The touch screen 318 and the control panel 320 allow a user(e.g., a medical provider, patient, etc.) to input various differenttreatment parameters to the hemodialysis machine 302 and to otherwisecontrol the hemodialysis machine 302. In addition, the touch screen 318serves as a display to convey information to the user of thehemodialysis system 300. A speaker 322 is positioned below the touchscreen 318 and functions to provide audio signals to the user of thesystem 300. Thus, the hemodialysis machine 302 is capable of providingboth visual alerts via the touch screen 318 and audio alerts via thespeaker 322 to the user of the system 300 during use. While the speaker322 has been described as being positioned below the touch screen 318,the speaker 322 could be positioned at any of various other locations onthe hemodialysis machine 302.

In some implementations, the touch screen 318 is an embodiment of thedisplay device 122 and the user interface 123 of FIG. 1. For example,the touch screen 318 can render the user interface 123 to allow a userto input the one or values associated with the patient/user fordetermining an estimated UFR. For example, before a dialysis treatmentbegins, the touch screen 318 can display graphics prompting a user toinput values for estimating an UFR, and based on those values, thehemodialysis machine 302 can determine an estimated UFR as describedearlier with reference to FIG. 2. The touch screen 318 can then displaythe estimated UFR. In some implementations, the visual alerts providedby the touch screen 318 are part of the alert module 124 of FIG. 1,where the touch screen 318 provides the visual alert (e.g., flashing redlight) in response to the estimated UFR exceeding the UFR thresholdvalue. In some implementations, the speaker 322 is part of the alertmodule 124, where the speaker 322 provides audible alerts in response tothe estimated UFR exceeding the UFR threshold.

A dialysate container 324 is connected to the hemodialysis machine 302via a dialysate supply line 326. A drain line 328 and an ultrafiltrationline 329 also extend from the hemodialysis machine 302. The dialysatesupply line 326, the drain line 328, and the ultrafiltration line 329are fluidly connected to the various dialysate components and dialysatelines inside the housing of the hemodialysis machine 302 that form partof the dialysate circuit. During hemodialysis, the dialysate supply line326 carries fresh dialysate from the dialysate container 324 to theportion of the dialysate circuit located inside the hemodialysis machine302. As noted above, the fresh dialysate is circulated through variousdialysate lines and dialysate components, including the dialyzer 310,that form the dialysate circuit. As the dialysate passes through thedialyzer 310, it collects toxins from the patient's blood. The resultingspent dialysate is carried from the dialysate circuit to a drain via thedrain line 328. When ultrafiltration is performed during treatment, acombination of the spent dialysate and excess fluid drawn from thepatient is carried to the drain via the ultrafiltration line 329.

The blood component set 304 is secured to a module 330 attached to thefront of the hemodialysis machine 302. The module 330 includes a bloodpump 332 capable of driving blood through the blood circuit. The module330 also includes various other instruments capable of monitoring theblood flowing through the blood circuit. The module 330 includes a door331 that when closed, as shown in FIG. 3, cooperates with the front faceof the module 330 to form a compartment sized and shaped to receive theblood component set 304. In the closed position, the door 331 pressescertain blood components of the blood component set 304 againstcorresponding instruments exposed on the front face of the module 330.

The dialysate circuit is formed by multiple dialysate components anddialysate lines positioned inside the housing of the hemodialysismachine 302 as well as the dialyzer 310, a dialyzer inlet line 400, anda dialyzer outlet line 402 that are positioned outside of the housing ofthe hemodialysis machine 302. The dialyzer inlet line 400 includes aconnector adapted to connect to one end region of the dialyzer 310, andthe dialyzer outlet line 402 includes a connector adapted to connect toanother end region of the dialyzer 310.

FIG. 5 is a schematic showing the flow paths of fluids into, through,and out of the blood circuit and the dialysate circuit of thehemodialysis system 300. The dialysate components of the dialysatecircuit that are located inside the housing of the hemodialysis machine302 include a first dialysate pump 404, a balancing device 406, apressure sensor 408, an equalizing chamber 410, a second dialysate pump412, and an ultrafiltration pump 414. These dialysate components arefluidly connected to one another via a series of dialysate lines 416.

The dialysate pump 404 is capable of pumping dialysate to the balancingchamber 406 via the dialysate supply line 326. In some implementations,the dialysate pump 404 is a peristaltic pump. However, any various othertypes of pumps can alternatively or additionally be used. Examples ofother suitable types of pumps include diaphragm pumps and gear pumps.

The balancing device 406 includes a spherical chamber that is dividedinto a first chamber half 418 and a second chamber half 420 by aflexible membrane 422. As fluid flows into the first chamber half 418,fluid is forced out of the second chamber half 420, and vice versa. Thisbalancing device construction helps to ensure that the volume of fluidentering the balancing device 406 is equal to the volume of fluidexiting the balancing device 406. This helps to ensure that the volumeof fresh dialysate entering the dialysate circuit is equal to the volumeof spent dialysate exiting the dialysate circuit when desired duringtreatment, as described in greater detail below.

During hemodialysis, the dialysate exiting the second chamber half 420is directed through the dialyzer 310 toward the equalizing chamber 410.The pressure sensor 408 located along the dialysate line 416 connectingthe dialyzer 310 to the equalizing chamber 410 is adapted to measure thepressure of the spent dialysate exiting the dialyzer 310. Any of variousdifferent types of pressure sensors capable of measuring the pressure ofthe spent dialysate passing from the dialyzer 310 to the equalizingchamber 410 can be used.

The spent dialysate collects in the equalizing chamber 410. Thedialysate pump 412 is configured to pump the spent dialysate from theequalizing chamber 410 to the first chamber half 418 of the balancingdevice 406. In some implementations, the dialysate pump 412 is aperistaltic pump. However, any various other types of pumps canalternatively or additionally be used. Examples of other suitable typesof pumps include diaphragm pumps and gear pumps. As the first chamberhalf 418 of the balancing device 406 fills with the spent dialysate,fresh dialysate within the second chamber half 420 is expelled towarddialyzer 310. Subsequently, as the second chamber half 420 is refilledwith fresh dialysate, the spent dialysate within the first chamber half418 is forced through the drain line 328 to the drain.

The ultrafiltration line 329 is connected to an outlet of the equalizingchamber 410. The ultrafiltration pump 414 is operatively connected tothe ultrafiltration line 329 such that when the ultrafiltration pump 414is operated, spent dialysate can be pulled from the equalizing chamber410 and directed to the drain via the ultrafiltration line 329.Operation of the ultrafiltration pump 414 while simultaneously operatingthe dialysate pump 412 causes increased vacuum pressure within thedialysate line 416 connecting the equalizing chamber 410 to the dialyzer310, and thus creates increased vacuum pressure within the dialyzer 310.As a result of this increased vacuum pressure, additional fluid ispulled from the blood circuit into the dialysate circuit across thesemi-permeable structure (e.g., semi-permeable membrane orsemi-permeable microtubes) of the dialyzer 310. In certainimplementations, the ultrafiltration pump 414 is a peristaltic pump.However, any various other types of pumps can alternatively oradditionally be used. Examples of other suitable types of pumps includediaphragm pumps and gear pumps.

FIG. 6 is a schematic of fluid flow through the blood circuit anddialysate circuit of the hemodialysis system 300 of FIG. 3 when thehemodialysis system 300 is connected to a patient for treatment. Duringhemodialysis treatment, the blood pump 332 is activated causing blood tocirculate through the blood circuit. The blood follows the same basicroute as the route of the saline described above and, for the most part,pushes the residual saline in the blood circuit through the variousblood components and blood lines and back to the patient. The blood isdrawn from the patient 450 via the arterial patient line 306 and flowsto the arterial pressure sensor capsule 354. The arterial pressuresensor 384 on the front face of the module 330 aligns with the pressuresensor capsule 354 and measures the pressure of the blood flowingthrough the blood circuit on the arterial side. The blood then flowsthrough the U-shaped pump line 360, which is operatively engaged withthe blood pump 332. From the pump line 360, the blood flows to thedialyzer 310. After exiting the dialyzer 310, the blood flows through avenous pressure sensor capsule 356 where the pressure of the blood onthe venous side is measured by the associated pressure sensor 386 on thefront face of the module 330 (shown in FIG. 9).

In certain implementations, a drug, such as heparin, is injected intothe blood via a drug delivery line 374 by activating a drug pump 392.Injecting heparin into the blood can help to prevent blood clots fromforming within the blood circuit. Other types of drugs can alternativelyor additionally be injected from the syringe 378 into the blood circuit.Examples of such drugs include vitamin D and iron supplements, such asVenofer® and Epogen®.

Next, the blood flows through an entry port of the air release device312 in which any gas, such as air, in the blood can escape. When theblood enters a chamber of the air release device 312, the blood forcesthe saline at the bottom of the chamber, which remains in the chamberfrom the priming procedure, through an exit port of the air releasedevice 312. However, the blood does not displace all of the salinewithin the chamber. Because of the size and shape of the chamber, theblood enters the chamber and only traverses part of the height of thechamber before flowing back down and exiting the exit port. Theinterface between the saline and the blood delineates the furthestextent of the vast majority of the blood within the chamber. Becauseblood and saline are not immiscible, there is some amount of mixingbetween the two fluids around the interface.

The saline substantially prevents the blood from contacting a membraneof the vent assembly 314. However, some blood can be present in thesaline without hindering treatment. That is, the saline need not becompletely free of blood for the air release device 312 to both allowgas (e.g., from air bubbles in the blood) to vent from the blood circuitand retain the liquid within the blood circuit. The solution that ismostly saline protects the membrane of the vent assembly 314 frombecoming coated with protein, which could clog the vent assembly 314 andreduce the ability of the air release device 312 to vent air and othergases from the chamber of the air release device 312 to the atmosphere.If the chamber of the release device 312 is sufficiently elongated, theblood does not mix with the saline at the top portion of the chamber 316because the saline remains relatively stagnant as the blood flowsthrough the chamber.

Any unbound gas, or air, that is in the blood, such as air that isintroduced by the dialyzer 310 or syringe 378, rises as tiny air bubbleswithin the blood and saline until the air eventually vents out throughthe vent assembly 314. The blood travels up and over the dam 346 ratherthan straight across the bottom of the chamber and out the exit port. Bydirecting the flow of blood upwards, the blood with air is not able toflow in and directly back out of the chamber 316 without flowing upwardsto at least a height greater then the height of the dam 346. The surfacearea of the dam 346 and the inner walls of the chamber encourage air,including microbubbles, to separate from the blood and exit the bloodcircuit through the vent assembly 314. After exiting the air releasedevice 312, the blood travels through the venous patient line 308 andback to the patient.

During hemodialysis, fresh dialysate is pumped into the dialysatecircuit from the dialysate container 324 via the dialysate supply line326 by running the dialysate pump 404. The fresh dialysate enters thesecond chamber half 420 of the balancing device 406. As spent dialysateenters the first chamber half 418 of the balancing device 406, the freshdialysate is forced out of the second chamber half 420 and toward thedialyzer 310 via the dialysate line 416. The dialysate passes throughthe dialyzer 310 at the same time that the patient's blood is passedthrough the dialyzer 310 on an opposite side of the semi-permeablestructure of the dialyzer 310. As a result, toxins, such as urea, aretransferred across a permeable structure (e.g., permeable membraneand/or permeable microtubes) of the dialyzer 310 from the patient'sblood to the dialysate, and those toxins collect in the dialysateforming spent dialysate. The spent dialysate exiting the dialyzer 310 iscirculated through the dialysate circuit to the equalizing chamber 410.The dialysate pump 412 draws spent dialysate from the equalizing chamber410 and delivers it to the first chamber half 418 of the balancingdevice 406. As the spent dialysate fills the first chamber half 418,fresh dialysate within the second chamber have 420 is delivered to thedialyzer 310. As the second chamber half 420 is subsequently refilledwith fresh dialysate, the spent dialysate within the first chamber half418 is forced out of the balancing device 406 and into a drain via thedrain line 328. The balancing device 406 balances the dialysate enteringthe dialysate circuit with the dialysate exiting the dialysate circuitto ensure that a substantially constant volume of dialysate remainswithin the dialysate circuit when ultrafiltration is not beingperformed.

In certain treatments, an ultrafiltration process is performed to removeexcess fluid from the patient's blood. During ultrafiltration, apressure gradient is created across the permeable structure between thedialysate side and the blood side of the dialyzer 310 by running theultrafiltration pump 414. As a result, fluid is drawn across thesemi-permeable structure of the dialyzer 310 from the blood circuit tothe dialysate circuit. Spent dialysate, including the toxins and excessfluid drawn from the patient, is drawn from the equalizing chamber 410by the ultrafiltration pump 414 and is delivered to the drain via theultrafiltration line 329.

While certain embodiments have been described above, other embodimentsare possible.

While the methods described above involve activating an audio alarm andvisual arm in response to detecting a malfunctioning device, an audioalarm alone or a visual alarm alone can alternatively be used to alertthe operator of the system to the malfunctioning device.

In some implementations, the air release device 312 and at least one ofthe other blood components and blood lines (e.g., all of the other bloodcomponents and blood lines) are incorporated into an integrated bloodcomponent set. The various components of the integrated blood circuitcan be formed together in one assembly or integrated molding rather thandiscrete separate or modular devices. The integrated blood component setcan be adapted to removably seat into the module 330 of the hemodialysismachine 302 in a manner similar to the blood component set 304 describedabove.

While the various blood components have been described as beingincorporated into an integrated blood component set, the bloodcomponents can alternatively be secured to a carrier body of thehemodialysis machine 302 or connected to one another by blood linesalone. In such implementations, the blood components would beindividually secured to the hemodialysis machine 302 (e.g., the module330 of the hemodialysis machine 302) prior to treatment. Thefunctionality of the blood components would be similar to thefunctionality of those blood components discussed above. Suitable bloodcomponent sets and their related components are described in greaterdetail in U.S. Patent Application Publication No. 2009/0101566, entitled“Dialysis Systems and Related Components,” which is incorporated byreference herein.

While the dialysate circuit has been described as being partiallyintegrated with the hemodialysis machine 302, the dialysate circuit canalternatively be formed by a dialysate component set that can beremovably secured to a hemodialysis machine during use. In someimplementations, the dialysate component set is in the form of acassette that can be inserted into a drawer of the hemodialysis machinein a manner such that the cassette operatively engages components of thehemodialysis machine when the drawer is closed. Such a dialysatecomponent sets is described, for example, in U.S. Patent Application No.61/231,220, entitled “Dialysis Systems, Components, and Methods” andfiled on Aug. 4, 2009, which is incorporated by reference herein.

While the dialysate supply line 326 has been described as carrying freshdialysate, the hemodialysis machine 302 can alternatively be configuredto generate dialysate from acid concentrate, bicarbonate concentrate,and purified water. For example, in some implementations, the dialysatesupply line 326 is coupled to an acid concentrate source, the drain line328 is coupled to bicarbonate concentrate source, and theultrafiltration line 329 is coupled to a drain. In such implementations,the hemodialysis machine 302 further includes a purified water inlet.The acid concentrate and the bicarbonate concentrate can be introducedinto the purified water to generate dialysate online.

While the air release device 312 of the extracorporeal blood circuitdiscussed above has blood entry port and a blood exit port in the bottomof the device, in some implementations, the air release device includesa blood entry port at the top of the device and a blood exit port at thebottom of the device.

While the dialysate circuit of the ECBT machine 302 has been describedas including aa balance chamber, a fresh dialysate pump, a spentdialysate pump, and a UF pump, in some implementations, the dialysatecircuit includes no balance chamber or separate UF pump. In suchimplementations, for example, the dialysate circuit can include a freshdialysate pump and a spent dialysate pump, such as impeller pumps, whosespeeds can be controlled to achieve a desired UF rate.

While the ECBT machine 120 and the hemodialysis machine 302 have beendescribed as including a touch screen, it should be appreciated that anyof the ECBT/hemodialysis machines described herein can alternatively beprovided with a conventional screen and an associated control panel,mouse and/or keyboard to allow the user to input data. Alternatively oradditionally, the hemodialysis machine can be equipped with a scratchpad and/or touch buttons that permit the user to input data.

While certain visual alarms have been described as being displayed viathe touch screen 318, the visual alarms can be displayed using othertypes of devices. For example, in implementations in which the dialysismachine includes a traditional screen (i.e., a non-touch screen) alongwith a separate device, such as a keyboard, for inputting data, thevisual alarm can be displayed via the traditional screen.

While the alert module 124 has been described as generating visualand/or audible alerts, alternatively or additionally, the alert module124 may include a biofeedback algorithm. The biofeedback algorithm canallow the alert module to control one or more operating parameters in ofthe ECBT machine 120 in accordance with the biofeedback algorithm byadjusting the one or more operating parameters such that the estimatedUFR is reduced.

In the foregoing description, embodiments of the invention have beendescribed with reference to numerous specific details that may vary fromimplementation to implementation. The description and drawings are,accordingly, to be regarded in an illustrative rather than a restrictivesense. The sole and exclusive indicator of the scope of the invention,and what is intended by the applicants to be the scope of the invention,is the literal and equivalent scope of the set of claims that issue fromthis application, in the specific form in which such claims issue,including any subsequent correction. Any definitions expressly set forthherein for terms contained in such claims shall govern the meaning ofsuch terms as used in the claims. In addition, when we use the term“further comprising,” in the foregoing description or following claims,what follows this phrase can be an additional step or entity, or asub-step/sub-entity of a previously-recited step or entity.

1-24. (canceled)
 25. A medical device, comprising a display device; acomputer-readable medium comprising computer-executable instructions;one or more processors configured to execute the computer-executableinstructions; an alert module configured to be communicatively coupledto the one or more processors and produce an alert; and one or moresensor devices communicatively coupled to the one or more processors;wherein, when the one or more processors are executing thecomputer-executable instructions, the one or more processors areconfigured to carry out operations to: receive, from the one or moresensor devices, one or more values associated with a user of the medicaldevice, the one or more values comprising a current weight of the user;determine an estimated post-treatment ultrafiltration rate based on theone or more values; compare the estimated post-treatment ultrafiltrationrate to an ultrafiltration rate threshold value; and in response todetermining that the estimated post-treatment ultrafiltration rateexceeds the ultrafiltration rate threshold value, adjusting one or moreoperating parameters of the medical device.
 26. The medical device ofclaim 25, wherein the one or more values associated with the usercomprises a target dry weight of the user.
 27. The medical device ofclaim 25, wherein the one or more values associated with the usercomprises an additional volume of fluid entering the user's body duringa treatment session.
 28. The medical device of claim 25, wherein the oneor more values associated with the user comprises an ultrafiltrationtime.
 29. The medical device of claim 25, wherein the medical device isa dialysis machine.
 30. The medical device of claim 25, wherein theultrafiltration rate threshold value is 13.0 mL/kg/hr.
 31. The medicaldevice of claim 25, wherein the one or more processors are configured todynamically determine the estimated post-treatment ultrafiltration ratewhile the user is undergoing treatment with the medical device.
 32. Themedical device of claim 25, wherein the one or more processors areconfigured to determine the estimated post-treatment ultrafiltrationrate according to the formula: $\frac{\begin{matrix}{\left( {{{Current}\mspace{14mu}{Weight}} - {DryWeightTarget}} \right)*} \\{1000 + {AdditionalFluidVolume}}\end{matrix}}{{UFTime}*{DryWeightTarget}},$ wherein CurrentWeight is thecurrent weight of the user, Dry Weight Target is a target weight for theuser after undergoing treatment, AdditionalFluidVolume is an estimatedvolume of fluid the user may receive during treatment, and UFTime is anamount of time the user will undergo treatment.
 33. The medical deviceof claim 25, wherein the one or more sensor devices comprise a weightsensor coupled to a seat portion of the medical device.
 34. A method,comprising: receiving, from one or more sensor devices, one or morevalues associated with a user of a medical device, the one or morevalues comprising a current weight of the user; determining an estimatedpost-treatment ultrafiltration rate based on the one or more values;comparing the estimated post-treatment ultrafiltration rate to anultrafiltration rate threshold value; and in response to determiningthat the estimated post-treatment ultrafiltration rate exceeds theultrafiltration rate threshold value, adjusting one or more operatingparameters of the medical device.
 35. The method of claim 34, whereinthe one or more values associated with the user comprises a target dryweight of the user.
 36. The method of claim 34, wherein the one or morevalues associated with the user comprises an additional volume of fluidentering the user's body during a treatment session.
 37. The method ofclaim 34, wherein the one or more values associated with the usercomprises an ultrafiltration time.
 38. The method of claim 34, whereinthe one or more sensor devices comprise a weight sensor coupled to aseat portion of the medical device.
 39. The method of claim 34, whereinthe ultrafiltration rate threshold value is 13.0 mL/kg/hr.
 40. Themethod of claim 34, wherein the estimated post-treatment ultrafiltrationrate is determined dynamically while the user of the medical device isundergoing treatment with the medical device.
 41. The method of claim34, wherein determining a post-treatment ultrafiltration rate comprisesusing the formula: $\frac{\begin{matrix}{\left( {{{Current}\mspace{14mu}{Weight}} - {DryWeightTarget}} \right)*} \\{1000 + {AdditionalFluidVolume}}\end{matrix}}{{UFTime}*{DryWeightTarget}},$ wherein CurrentWeight is thecurrent weight of the user, Dry Weight Target is a target weight for theuser after undergoing treatment, AdditionalFluidVolume is an estimatedvolume of fluid the user may receive during treatment, and UFTime is anamount of time the user will undergo treatment.
 42. The medical deviceof claim 25, wherein the operations further comprise: in response todetermining that the estimated post-treatment ultrafiltration rateexceeds the ultrafiltration rate threshold value, controlling at leastone of (i) the display device to display a visual alert or (ii) aspeaker of the alert module to emit an audible alert.
 43. The method ofclaim 34, further comprising: in response to determining that theestimated post-treatment ultrafiltration rate exceeds theultrafiltration rate threshold value, controlling at least one of (i) adisplay device of the medical device to display a visual alert or (ii) aspeaker of an alert module to emit an audible alert.
 44. The method ofclaim 34, wherein adjusting one or more operating parameters of themedical device comprises adjusting the one or more operating parametersto reduce the estimated post-treatment ultrafiltration rate.